Gardeners love lobelia for its cascading flowers and low-maintenance needs. And a healthy garden of lobelia starts with suitable starter plants. When in the nursery, look for lobelia that is short and stocky with plenty of leaves and no flowers. These plants are best suited for growing strong roots and establishing themselves quickly. Plant them in early spring in fertile soil, and they will quickly grow into full and luxurious plants.
Dig holes that are twice as deep and twice as wide as the containers that your lobelia plants are growing in. Large varieties of lobelia should be 2 feet apart but small ones can be planted as close as 4 inches.
Mix half of all the excavated soil with an equal amount of aged organic compost.
Back fill the soil mixture into each of the holes so that the plants can be planted at the same depth as they were in the container.
Carefully remove each plant from its container. The best way to do this is to loosen the soil by pressing the sides of the container before gently pulling the plants out.
Plant each plant and fill the soil so that it is at the same level as it was when growing in its container.
Water the lobelia plants so that the soil is always kept moist.
Deadhead lobelia's flowers to force it to continue to flower all summer long. If your lobelia stop blooming, cut the plants back to half their size. When the weather cools down, the plants will bloom again.
Dig up and compost your lobelia after the frost kills them in late fall.